Breakthrough technology has emerged which allows the navigation of a catheter tip through a tortuous channel, such as those found in the pulmonary system, to a predetermined target. This technology compares the real-time movement of a locatable guide (LG) against a three-dimensional digital map of the targeted area of the body (for purposes of explanation, the pulmonary airways of the lungs will be used hereinafter, though one skilled in the art will realize the present invention could be used in any body cavity or system: circulatory, digestive, pulmonary, to name a few).
Such technology is described in U.S. Pat. Nos. 6,188,355; 6,226,543; 6,558,333; 6,574,498; 6,593,884; 6,615,155; 6,702,780; 6,711,429; 6,833,814; 6,974,788; and 6,996,430, all to Gilboa or Gilboa et al.; U.S. Published Applications Pub. Nos. 2002/0193686; 2003/0074011; 2003/0216639; 2004/0249267 to either Gilboa or Gilboa et al; as well as U.S. patent application Ser. No. 11/939,537 to Averbuch et al. All of these references are incorporated herein in their entireties.
Using this technology begins with recording a plurality of images of the applicable portion of the patient, for example, the lungs. These images are often recorded using CT technology. CT images are two-dimensional slices of a portion of the patient. After taking several, parallel images, the images may be “assembled” by a computer to form a virtual three-dimensional model of the lungs.
The physician then takes this virtual model and, using the software supplied with the navigation system, plans a path to the target. Planning the path to the target involves creating a patient file and selecting and saving various waypoints along the path to the target. The physician also selects and saves various registration points used by the software to register the virtual model to the actual patient in the upcoming procedure.
Typically, there is only one path that leads to the target, unless the target is very large. In the airways and vasculature of the body, the body lumina do not split and then rejoin downstream. The branches of a tree provide a good analogy: for any given leaf on a tree, there is only one combination of branches that lead to that leaf. Hence, the step of pathway planning is a time-consuming step that would be avoided if automated.
Additionally, the present systems provide guidance to the target, but not necessarily to the waypoints along the way. Instead of focusing on the target, it would be advantageous to provide navigation guidance to each of the intermittent waypoints, thereby treating each successive waypoint as a target, then, after the waypoint is reached, changing the target to the next waypoint.